So you say the WiiU needs 300k units to catch up. There are ~9 weeks untill the end of October. That's more than 30k units the WiiU needs to sell more than the XBO.
The WiiU lineup for that time is Hyrule, Just dance, Disney Infinity, Lego, Skylanders and Bayo.
XBO has Destiny, every yearly sports game, Forza, Mordor, Alien Isolation, Evil Within, Sunset Overdrive and a shitton of other games (including everything the WiiU has thats not hyrule and bayo).
Considering this and that they are selling about the same amount of units at the moment, i really doubt the WiiU will be able to pull out an extra 30k a week on the XBO. just seems unlikely.
p.s. yes nintendo consoles do get a bigger holiday boost but october is not holiday yet.